Improvement in navigators  bearing-indicators



J'. D. LEACH. ITA/'IGA'IIORS:BEARIN'C'rrI1\TDI`J.AT0L7{,. No.170,001,Patented Nov.16,1875.

F/GJ

N. PETERS. PHOTO-UTHOGRAFHER. WASHINGTON, D C,

'UNITED STATES PATENT OFFICE.

JOSEPH D.v LEAOH, OF `PENOBSOOT, MAINE.

IMPROVE'MENT lN NAVIGATORS BEARING-INDICATORS..

Specification forming partot' Letters `Patent No. 170,001, datedNovember 16, 1875; application filed May 17, m75.

equivalents: A bed-plate constructed and ar-1 ranged to be readilyremoved or iixed in position upon the part ofthe vessel from which theobservation can be most conveniently made, this bed being provided witha iixed point, tel'med the lubber-mark, by which to adjust the revolvingcard, and a locking-screw for securing the card in position. This cardrevolves upon the central standard, and is subdivided into points, andmarked like the common compass-card. The standard is secured andrevolves in the center of the-bed, and at its base is provided with alocking-screwand indicating-point, which moves over the face of the cardas the standard is revolved, and is locked in any desired position bythe locking- Screw. In the top oi' this standard is pivoted4 (to allow avertical adjustment) a tube' provided at one end with an eye-piece, andat the other with the usual cross-hairs, or with fine Wires. Upon thistube are holders, in which a telescope maybe laid, in the direction ofthe tube, and secured for use, when such an instrument may be necessary.

Figure 1 is a vertical section taken in the axial line ot' the tube.Fig. 2 is a top or plan view, with the sighting-tube partly broken awayto show the movable indicating-point.

The bearing-indicators heretofore invented and patented by myself wereonly useful upon vessels in which the wheel was in the forward part, asthey could only be used in direct connection with the compass; and henceupon vessels in which the steering-wheel is near the rudder-head, or aftthe sails, they could only be used when the object to be observed wasbroad oft'77 the beam or quarter, as the sails obstructed the viewforward, so that the'indicator could but seldom be used. To remedy thesedefects I have invented my present indicator, which in no case is usedin connection with the compass, and which may be used upon any desiredpart of the vessel, such as the tat't'- rail, the rail upon thequarters, the bows, amidship, the windlass-bitts, or at the mast-head,`by simply providing` the means of .placing it in position, thus givingthe navigator its full beneiit, without regard to the position ol' theobject relatively to the vessel, and'enabling him to determine theposition ot such object with the same accuracy that he determines thecourse his vessel is pursuing.

In the drawings, a is a section of the vessels rail, or a bed-piece tobe secured to the vessel. b b are two pins, which are inserted in bed a,and which receive the ears c c ot' the indicator-bed (l, when it isplaced in position for use. The pins b b must be so placed that a linepassing through the center ot' each shall be exactly parallel with themidlship or central fore-and-aft line of the vessel. e is'thelubber-mark, a pin or indicator iixed in the raised rim or periphery ofbed d, and exactly in the central line ot pins b. fis a set-screw,threaded in bracket g, 'and serving to lock the card 7L in` position.This card is marked with the usual compass-points, as shown in Fig. 2,or in such other equivalent manner as serves tot'acilitate its use. Thiscard, when not locked by screw f, may be freely rotated upon bed d bymeans of pin i, secured in the card. j is the standard, pivoted andrevolving in bed d, to which it is secured by screw-nut k. A set-screw,l, threaded in the base ofthe standard, and acting upon bed d, serves asthe means ot locking the standard in position. m is apointer, formedupon or attached to the standard. n is the si ghtin g-tube, pivoted tothe standard at 0, and ertically adjustable. This tube must exactlycoincide with a line passing through the center of the standard and theend ot' pointer m. p represents the cross-hairs, and r the eye-piece. sis a telescope, which, when used, is laid in the curved bearings t t,secured upon tube n, a strap, u, serving to secure the telescope inplace.

The practical use of this indicatorI will illustrate by reference toFig. 2 in the drawings. Suppose the course to be pursued is due northuntil the object or land-mark bears northwest,

(when that course will be taken,) and that the vessel .has reached theposition where she should haul up on the new course-the navigator, toverify this fact, will so adjust the card that the north point is at thelubber-mark e, as shown, and the card Will be so locked. The indicatoris placed in position upon pins b, with the north point toward the headof the vessel, and the sightil1gtube 'it' brought to bear upon theland-niark7 When. itin the night7 it would be looked by screw l, and theindicator' taken to the light, and the pointer m being found upon thenorthwest point, would show that the Vessel should then be hauled up onthe new course; but it in this supposed case the pointerml had beenfound to the West ot' northwest it would show that the vessel had notarrived at the point for changing its course,

is sailing, and then placing the indicator in position with point etoward the head of the vessel, when, by bringingl the sighting-tube tobear upon the land-mark, the pointer m will always indicate upon thecard h thedirection (by compass) of such land-niark from the ves'- sel.

The telescope s may be used in the same manneras tube uri-u connectionwith the indicator. v

Wherever upon the vessel a pair of pins, b, are fixed parallel with thecentral line of the ves-sel, there the indicator may be used with thecertainty oi' correct results.

I do'' not claim an indicator to be used in connection With the shipscompass, as described in my said patents; but

' What l do cla-iin as my invention islna bearing-indicator, thecombination ot' bed d, lulober-mark e, locking-screw f, ears c c,

rotating' standard j, locking-screw l, pointer m,

pivoted sighting-tube n, and cord h, substantially as described andshown. n

JOSEPH D. LEAOH. Witnesses:

CALVIN DAVIS, SEWALL LEAcH.

